Paper-making machine



No. 551L421. Patented Sept. 27, I898.

' T. H. SAVERY.

PAPER MAKING MACHINE.

(Application mm Nov. 14, 1896.)

(No Model.)

TH: cams warms c0 PHOTOLITNOH wAsmNcToN, o. c,

Mrs STATES v union.

PAPER-MAKING MACHINE.

SPECIFICATION forming part of Letters Patent No. 61 1,421, datedSeptember 27, 1898.

Application filed November 14, 1896. Serial No. 612,099. (N model.)

To all whom it may concern:

Be it known that I, THOMAS H. SAVERY, a citizen of the UnitedStates,'residing in the city of Wilmington, county of New Castle, andState of Delaware, have invented certain new and useful Improvements inPaper-Making Machines, fully described and represented in the followingspecification and the accompanying drawings, forming a part of the same.

This invention relates to paper-makin g machines, and more particularlyto an improvement upon the subject-matter of my application, Serial No.612,098, executed and filed of even date herewith.

The object of the present invention is the rapid and continuous removalof the water which is expelled from the forming paper through pressureapplied thereto bythe moving cylindrical surfaces between which itpasses, and which water enters into the angular space existing betweenthe carrying-felt and the couch-roll of a cylinder-machine, between theforming-wire and the couch-rolls in a Fourdrinier machine,and betweenthe carrying-felt and the press-rolls in all papermaking machines andwould exist between press-rolls if the carrying-felt were omitted. Thisangular space constitutes a recess at the front or entrance side of suchrolls in which a body of this expelled water ordinarily accumulates andis maintained and from which it is thus enabled to reenter the paperstock or stuff or its traveling support or carrier thereof, from eitheror both of which it was derived, and thereafter act injuriously bystaining the forming paper by rewetting the paper stock or stuff or itssupport or carrier, and thereby necessitating more extended operationsin the forming of the paper or rendering the devices which aid in theformation of the paper defective in their operation.

The invention consists of a pneumatic appliance for continuouslyremoving water from said recess, whereby the water received thereininstead of accumulating there is constantly discharged therefrom, andthus is prevented from returning to the paper stock or stuff or to thedevices operating in connection therewith and injuring the paper orcausing defective action of said devices, all of which, together withthe benefits consequent upon this invention, arehereinafter fully setforth.

The specific embodiment of this invention herein embraced is a pneumaticappliance which, broadly stated, is a means for removing thisobjectionable body of water by the operation of air thereon, and morelimitedly set forth is the provision of said recess with an air-exhaustapparatus whereby the water when received within said recess from theforming paper is rapidly removed therefrom and discharged from themachine.

Preferable embodiments of this invention are illustrated in theaccompanying drawings,

wherein Figure 1 is a diagrammatic side elevation showing the same asapplied to a cylinder paper-making machine. Fig. 2 is a similar viewshowing the said invention as appliedto the couch-rolls of a Fourdriniermachine. Fig. 3 is a similar representation. of a first pair ofpress-rolls applicable to either a cylinder or Fou rd rinier machin eand provided with this invention. 7 Fig. 4 is a similar representationof .a second pair of press-rolls similarly equipped. Fig. 5 is asectional elcvation,onehalf ordinary practical size, of so much of acylinder paper-machine as will exhibit the relation of itsforming-cylinder, couch-roll, web of stuff, forming-felt, and thepneumatic appliance in their corelations. Fig. 6 is alikesized elevationof part of the pneumatic appliance, couch-rolls, endless wire apron, andstuff or stock. Fig. 7 is'a like-sized elevation of part of thepneumatic appliance, first pressrolls, and endless felt. Fig. 8 is alike-sized elevation of part of the pneumatic appliance, secondpress-rolls, and endless felt; and Fig. 9 is a plan view of a modifiedform of the pneumatic appliance.

It will be observed in the case of a cylinder machine (illustratedinFig. 1) that the form ing-cylindewl is a reticulated cylindricalsurface, which in practice turns in a vat (not shown) and for the mostpart is immersed in a mass of diluted pulp or stuff constantly suppliedthereto, as is common. This forming-cylinder is surmounted by anothercylindrical surface or couch-roll 5, and the forming-felt 6, which runsunder and returns over the couch-roll, also passes in contact with thetop of the forming-cylinder, and consequently since the film of fibersor web of stock or stuff 3 taken up by the formingcylinder upon itsonwardly-moving surface is first carried against the under side of theforming-felt 6 and passes therewith to and between the cylindricalsurface of the forming-cylinder 4 and that of the couch-roll 5 itresults that the pressure thus exerted upon it expels from it a largeportion of the water it then contains, much of which water will passupwardly through said forming-felt 6 and be received in the recessformed at the front side of the couch-roll 5 and between it and theforming-felt 6, as is best understood from Fig. 5. While the water thusdelivered into this recess and accumulated on top of the felt 6 may haveits excess spread rearward upon said felt 6 and be carried off the samefrom the sides thereof, there will always be a portion of thisaccumulating body of water retained in said recess sufficient tosubstantially fill it, such water being maintained therein either bygravity, owing to the fact that said recess is lower than the plane inwhich that portion of the felt 6 rearward of it runs, or by the actionupon the water of the forward travel of the felt 6 on the cylinder 4 orby the onward movement of the surface of the couch-r0115, or both con jointly. Such a body of water maintained in this recess will either bycapillary attraction, greatly aided by the damp condition of the felt 6,its onward movement, or the forward travel of the cylindrical surface ofthe cylinder 4 and that of the couch-roll 5, reenter the wet web ofstock or stuff from which it was expressed and stain the same, whetheror not it has accumulated impurities, and thus damage it, or retard theforming operation. In order to constantly remove this water from saidrecess and the similar ones at pairs of cylindrical surfaces, ascouch-rolls 7 8 and press-rolls 11 12 or 13 14, and to keep it clearthereof, so as to avoid not only its defective action but form the paperas dry as possible at each stage of the operation thereon where water isexpelled therefrom, such recess (it may be one or more in each machine)is provided with a pneumatic apparatus operating,

to remove the water as it is received in such recess and thus keep thesame free and clear of it.

The illustrative pneumatic apparatus in the form shown consists of ahollow or box-like structure provided at its forward end with an openingor mouth extending the full length,

or nearly so, of the said recess, and so reachfrom said chamber. Ofcourse, if found necessary, this chamber might be perforated at asuitable point or points sufficiently to admit air to aid its practicaloperation; but it will ordinarily be found that there will be leakagesufficient past one or the other or both of its lips 1 2 to promote asuitable draft that will eifect the removal of the water entirely fromthe said recess and as rapidly as it accumulates therein or it isexpelled from the wet stock or stuff 3 and passed into such recess, andto effect this leakage past the preferred one of these lips the othermay be made of stiffer material, so as to hold its place close to or incontact with the roll and the felt or wire, as the case may be. Thereare many devices or apparatus by which this movement of water can beeffected through the force of air either acting by suction or pressure;but as a pressure apparatus adapted for this purpose is made thesubject-matter of another application it is only alluded to herein toindicate the scope of the present invention, and the suction or draftforce of air and the appliance for so using it will be set out hereinand specifically claimed.

Referring now to the pneumatic appliance shown in reduced scale by Fig.1 as applied to a forming-cylinder 4t and its couch-roll 5 andillustrated in Fig. 5 at a half-normal size, it will be observed that asthe movement of the water expressed from the saturated web of stock orstuff 3 is upward through the felt 6 the airappliance must be adapted tothat condition of affairs. A structure suited thereto is shown asconsisting of a chamber provided with a pipe 20 and closed on all sidessave where its mouth or orifice embraces or taps the said recess betweenthe forming-felt and the couch-roll, and the lips 1 2 of its month arepreferably caused to contact, re-

spectively, with the surface of the felt 6 at its bottom and with thesurface of the couchroll 5at its top, a constant draft or inductionthrough it being caused by the action of the pump or otherair-current-producing apparatus that is connected with the pipe 20. Itmay now be understood that as this formingcylinder 4 slowly turns in itsvat' in the direction of its arrow its action will be to take up uponits side, as indicated in Fig. 1, a film orstrata of fibrous stuff orstock 3 that is surcharged with water and carry the same in web-likeform upward and onward toward the couch-roll 5. This stock or stuff inpassing between the top surface of the formingcylinder 4 and the undersurface of the forming-felt 6, which is an endless apron that travelsover said couch-roll, will be simultaneously pressed between thesedevices and caused to adhere to the felt 6. At the same water uponcoming within the range of the passing current being at once carriedrearward thereby through the pipe 20 and discharged with the saidair-current. This aircurrent thus acts continuously to remove whateverwater enters the said recess and comes within the range of action of theair, which in practice is found to be equal to the entire removal ofthis water, which fact therefore prevents its accumulation in saidrecess to produce any faulty action.

It is preferable to cause the induction of air in excess of that whichaccompanies the water or otherwise leaks into the recess to enter theair-chamber between its upper lip 2 and the couch-r0115, for the reasonthat the direction or guiding of said air by the curved surface of thecouch-roll will be such as to aid its entering to the extreme forwardpoint of said recess and thus so act that it may thoroughly clean thesame as it takes its out: ward movement for discharge. It may, however,take such air from between the lower lip 1 and the felt 6 or partiallypast both the upper and lower lips.

Regarding now Fig. 2 and the sectional enlargement of its parts in Fig.6, the air-chamber will be found to be slightly modified to suit therelative disposition of the couch-rolls 7 8 and the wire apron 9, aswill be apparent from an inspection thereof, and it may be remarked thathere it is desirable to have the excess of working air necessary to thepractical operation come from between the lower lip 2 of the mouth ofthe air-chamber and the lower couch-roll 8, not only so as to compel thebest direction of the air, but to avoid any great current near the wireapron outside of the air-chamber; but the surplus supply of air may passeither or both of said lips, as before explained. In practice it will befound that the stretch of the wire apron 9 over a portion of the lowersurface of the upper couch-roll 7 will cause some water to be given offbefore this pneumatic device is reached and descend into the floor-vatbeneath and that the nip of the two couch-rolls 7 8 will by theirpressure expel from the stock or stuff itself additional water, whichwill flow into the recess that exists between these couchrolls at theirfront or entrance side and be removed by the air drawn through theairchamber by the pipe 20, which will operate in manner as beforeexplained; but in some cases, if found desirable, the mouth of thisair-chamber may be enlarged in its scope, so as to remove not only thewater from this recess as rapidly as it is received therein, but

such water as is freed by such stretch of the apron, and discharge thesame out of the machine. This air device as appliedto pressrolls, as 1112 and 13 14, is exhibited in reduced form by Figs. 3 and 4t and inone-half normal size by Figs. 7 and 8 and will, although it operates inconnection witha felt, as 15 or 16, perform in the same way ashas beenexplained with reference to the couch rolls,

though the appliance itself in consequence of the diminished amount ofwater respectively expressed by these press rolls in succession may bemade relatively somewhat smaller.

As illustrated, the air-chamber 10 is shown:

of air used or its pressure, which may thus be made to difier in forceatdifferent places, which is sometimes desirable. It is also important,especially when this air apparatus is used in connection withpress-rolls and because of the freedom with which the water expressed bythem may pass from between them at their ends and become absorbed by theoverhanging felt, to exert a greater degree of exhaust near the ends ofthe rolls than is used throughout the main portion thereof, and for thisreason it is desirable to divide the air-chamber into sections, so thatby suitable pipes and means for controlling the passage of the airtherethrough the draft of air may be made greater at some points than atothers. This is shown in the structure illustrated in Fig. 9, where theair-chamber is divided by two partitions into three subchambers 25 26 27,so that the exhaustive power of the air may, through suitable pipes 203O 50, be made to differ in each subchamber and have greater force atthe ends than in the middle, if desired.

Concerning the damaging elfect of water made use of in the production ofpaper it is to be noted that where water, even though it be pure, isallowed to soak into a paper web by moving backward into the same afterit has been expelled therefrom it has the effect to impart to the webstains that present in regular bounds or form waved,lines, which are thelimits to which this returning water extends before it is so farabsorbed as to cease its movement. These stains are readily perceived inthe finished paper and cause the sections of the web containing them tobe useless,which damaging action of thewater, pure or impure, isprevented by this invention.

In some cases the stock or stuff undergoing formation into paper may beso far freed from water as its leaves the couch or first press rollsthat it can be led to and passed through the first or second press-rollswithout the aid of a carrying-felt, in the absence of which felt thisinvention will coact with the paper web, stock or stuff, and apress-roll and operate to almost completely remove its remainingdampness, and such arrangement is therefore comprehended by thisinvention. By the use of this invention the water is removed from saidrecess as rapidly as it is expressed from the stock or stuff by meanswhich have a positive action thereon, and the following advantageousresults are obtained: A high speed of production may be attained, forthe reason that the paper becomes stronger because drier at all stagesof its formation. Larger couch and press rolls may be employed, thenumber of sets of press-rolls may be reduced, and a less extent ofdrying-surface be required or less heat needed for the drying operation.

Another and important beneficial effect is produced by this improvementupon the endless'felts, which in order to produce the best results aremade wider than the press-rolls are long,whence it results, since suchprojecting parts are not clamped between the rolls, but, on thecontrary, are free and therefore in the best condition to readily absorbwater if the same is present in said recess between the press-rolls. Theresult is when the water is present there and the edges of the feltbecome charged with it they not only carry the water onward and flirt itover the machine, but in consequence of such wet edges being in contactwith the paper web after it has passed the press-rolls they give off thewater they carry to the edges of the paper and thus impregnate theotherwise drier body of the web with water, so that the pressing anddrying thereof must be great enough for the treatment of the wet edgesor, otherwise stated, in excess of what is required for the bodyportion.

In consequence of the fact that this improvement prevents the return ofpractically all water that is once removed from the stock and the wireor felt carrying the same with the advantages already stated it alsoresults in causing the forming paper to be made drier in the earlierstages of and throughout its formation, and therefore enables its courseof travel to be lessened and permits of a reduction of the great lengthin which these machines are now constructed.

The application of these improvements to a paper-machine enablesstronger paper to be made, because being formed drier it does notrequire to be heated so much and injured thereby. It enables more paperto be made in a given time, because in the web state it is drier, andhence not so liable to break and make waste. It saves the felt of thedriers from injury, because a lower degree of heat may be used, and thepaper when led to them not being so wet as when made by a machinewithout this improvement there is less Wetting and consequent drying ofsaid felts, which rots them. It improves the quality of the paper byrunning faster, because there is less water to take out of it during thegreater portion of its formation, and by its action it keeps impuritiesfrom entering the felts and thus soiling them, so that they requirefrequent washing, which is detrimental in that felts frequently washedare thereby worn out and rendered useless, and it prevents the edges ofthe press-felts from receiving water and carrying it into the borders ofthe paper beyond the rolls.

It maybe desirable to provide the lips 1 and 2, either or both, with afacing of leather, rubber, or similar material having the requisitestrength and pliability for contact with the parts they may bear againstin order to prevent injury thereto or produce a proper joint therewith.

Although broadly embraced herein, the pneumatic appliance employing ablast of air for carrying out this invention is reserved as thesubject-matter of another application, Serial No. 612,100, filed by meof even date herewith.

What is claimed is- 1. The combination with cylindrical surfaces betweenwhich wet stock is fed and by the action of which the liquid isexpressed from the stock into the recess between the surfaces, of apneumatic appliance exterior to said surfaces and operating to removethe liquid directly from the said recess, substantially as described.

2. The combination with a traveling support, of cylindrical surfacesbetween which wet stock is fed by the traveling support whereby theliquid is expressed from the stock into the recess between the surfaces,and a pneumatic appliance exterior to said surfaces and operating toremove the liquid directly from the said recess, substantially asdescribed.

3. The combination with cylindrical surfaces between which wet stock isfed whereby the liquid is expressed from the stock into the recessbetween the surfaces at the entrance side thereof, of a pneumaticsuction appliance exterior to said surfaces and acting to remove theliquid directly from the said recess, substantially as described.

4.. In a paper-making machine, the combination with a traveling support,of cylindrical surfaces between which wet stock is fed by the supportwhereby the liquid is expressed from the stock into the recess betweenthe surfaces at the entrance side thereof, and a pneumatic suctionappliance exterior to said surfaces and operating to remove the liquiddirectly from the said recess, substantially as described.

5. In a paper-making machine, the combination with cylindrical surfacesbetween which wet stock is fed and by the action of which the liquid isexpressed from the stock into'the recess between the surfaces at theentrance side thereof, of a pneumatic appliance consisting of a chamberprovided with a mouth or orifice, the said mouth or orifice beinglocated exterior to said surfaces and acting to remove the liquiddirectly from said recess, substantially as described.

6. In a paper-making machine, the combination with a traveling support,of unbroken cylindrical surfaces between which wet stock is fed by thesupport whereby the liquid is expressed from said stock into the recessbetween the surfaces at the entrance side thereof, and a pneumaticappliance consistpneumatic appliance consisting of a chamber divided bypartitions into subchambers each subchamber being provided with a mouthor orifice which is exterior to said surfaces and which operates toremove the liquid directly from said recess, and connections whereby adifferent degree of air force is exerted in some chambers to that whichis exerted in other chambers, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

THOMAS H. SAVERY.

Witnesses: S. WINTHAL, J. J. KENNEDY.

